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Having now owned two houses with underfloor heating I'm convinced that this is The Way Forward. We are now in the throes of having a new house built which means, in France, that it has to be constructed to the new low energy norms here (RT2012). Right from the outset we said that I wanted underfloor heating but the construction company's engineers and architects advised against it due to a) the degree of insulation that these houses are required to have and b) the problem of inertia with regards thermostatic control of the heating/screed heating up. They advise an air > air heatpump for the large kitchen/living/dining/room plus electric radiators in the smaller rooms.
I like the feeling of the warmth coming from the ground up and not starting around my knees but the architect assures me that the floor (ceramic tile) won't feel cold like a normal house. I'm not convinced and we feel that to not have u/f is a backward step - and one that is totally irreversible. Can anyone - house owners, architects/heating engineers... anyone - offer any comments on this?
Thanks.
I like the feeling of the warmth coming from the ground up and not starting around my knees but the architect assures me that the floor (ceramic tile) won't feel cold like a normal house. I'm not convinced and we feel that to not have u/f is a backward step - and one that is totally irreversible. Can anyone - house owners, architects/heating engineers... anyone - offer any comments on this?
Thanks.
In reply to jon:
How are they proposing to get the heat from the heat pump into the room? Hot water radiators? Generally, underfloor heating couples really well with heat pumps, as you get the heat out without requiring a high temperature like hot water radiators. The problems your architect is describing sounds like the problems that are generally associated with underfloor heating, that I suspect you're already familiar with (i.e., you can't come home, think "gosh it's cold in here", crank up the heat and expect it to be warm in half an hour).
How are they proposing to get the heat from the heat pump into the room? Hot water radiators? Generally, underfloor heating couples really well with heat pumps, as you get the heat out without requiring a high temperature like hot water radiators. The problems your architect is describing sounds like the problems that are generally associated with underfloor heating, that I suspect you're already familiar with (i.e., you can't come home, think "gosh it's cold in here", crank up the heat and expect it to be warm in half an hour).
In reply to Green Porridge:
No, they propose a single wall mounted unit that blows hot air into the room. That's another thing - u/f is silent.
Yes, it's the delay in the floor heating up. My own experience is that I leave it on all the time set at a low temperature - it was on 15° in our chalet in the alps, topped up with a wood stove. Now in this very old stone built house it's set on 20° as we lose a lot through the walls. They say if I do this with a RT2012 house I'll be far too hot!
No, they propose a single wall mounted unit that blows hot air into the room. That's another thing - u/f is silent.
Yes, it's the delay in the floor heating up. My own experience is that I leave it on all the time set at a low temperature - it was on 15° in our chalet in the alps, topped up with a wood stove. Now in this very old stone built house it's set on 20° as we lose a lot through the walls. They say if I do this with a RT2012 house I'll be far too hot!
Post edited at 16:36
In reply to jon:
...and if it is, then you'll turn it down! The only thing I can think of which would be an argument for hot air heating would be that you might be able to combine it with the ventilation system (a lot of low energy/passive houses are very well sealed, and therefore require an active ventilation system) The house being well insulated shouldn't count as a reason not to have underfloor, underfloor will almost certainly be more complicated and expensive to install, but if that's what you want, and you're willing to pay for it, then I can't think of a reason not to.
...and if it is, then you'll turn it down! The only thing I can think of which would be an argument for hot air heating would be that you might be able to combine it with the ventilation system (a lot of low energy/passive houses are very well sealed, and therefore require an active ventilation system) The house being well insulated shouldn't count as a reason not to have underfloor, underfloor will almost certainly be more complicated and expensive to install, but if that's what you want, and you're willing to pay for it, then I can't think of a reason not to.
In reply to Green Porridge:
Yes, exactly that.
> The only thing I can think of which would be an argument for hot air heating would be that you might be able to combine it with the ventilation system (a lot of low energy/passive houses are very well sealed, and therefore require an active ventilation system)
Yes, exactly that.
In reply to jon:
Well, in that case, you could have underfloor and in addition to that an active ventilation system with a heat exchanger to minimise the losses. It's all possible, and if you like your underfloor heating, then do it. It's probably more expensive, and complicated to install, but if you want it and can afford it, then why not. The argument that it will be too hot is, as far as I can see, not really justified.
Well, in that case, you could have underfloor and in addition to that an active ventilation system with a heat exchanger to minimise the losses. It's all possible, and if you like your underfloor heating, then do it. It's probably more expensive, and complicated to install, but if you want it and can afford it, then why not. The argument that it will be too hot is, as far as I can see, not really justified.
Post edited at 16:59
In reply to jon:
I´ve had underfloor, its dead common here in Germany. But with low-energy houses (not too sure we´d call RT2012 "low energy" though) the relatively low thermal mass in the walls and their high insulation value the moment the sun comes out you cook because the underfloor heating is still working due to the thermal inertia. Conversely if you have a long period of sunny weather and then a cold breakthrough you freeze for a day or two. They tried with outside thermostat regulation systems but they were absolute crap!
The modern trend is for underfloor above the insulated screed or wall systems directly under the skim as they react quicker but you really need some sort of air heating system with air exchange to control the the humidity and provide the nescessary fresh air as well, your new house is a hermetically sealed object and to get its certificate it needs to have controlled ventilation with energy recovery (at least that´s what happens here).
I´ve had underfloor, its dead common here in Germany. But with low-energy houses (not too sure we´d call RT2012 "low energy" though) the relatively low thermal mass in the walls and their high insulation value the moment the sun comes out you cook because the underfloor heating is still working due to the thermal inertia. Conversely if you have a long period of sunny weather and then a cold breakthrough you freeze for a day or two. They tried with outside thermostat regulation systems but they were absolute crap!
The modern trend is for underfloor above the insulated screed or wall systems directly under the skim as they react quicker but you really need some sort of air heating system with air exchange to control the the humidity and provide the nescessary fresh air as well, your new house is a hermetically sealed object and to get its certificate it needs to have controlled ventilation with energy recovery (at least that´s what happens here).
In reply to jimtitt:
Ah. that was just my translation. Theyr'e called BBC here. Bâtiment de basse consommation. What should the term be?
Yes, that just about sums up what he said! So, not a good idea, then? What about my cold feet? Will they be warm if the floor is insulated enough? So he's not telling porkies, then?
Well that's interesting as the system we have in this little house is called Raychem Tyco T2 Reflecta. It's a heating cable set into an insulation sheet which goes on TOP of the screed. You then tile directly over it. As you say it heats up very quickly (and cools equally quickly) but it sounds really hollow - not nice and solid like a tiled floor should.
> low-energy houses (not too sure we´d call RT2012 "low energy" though)
Ah. that was just my translation. Theyr'e called BBC here. Bâtiment de basse consommation. What should the term be?
> the relatively low thermal mass in the walls and their high insulation value the moment the sun comes out you cook because the underfloor heating is still working due to the thermal inertia. Conversely if you have a long period of sunny weather and then a cold breakthrough you freeze for a day or two. They tried with outside thermostat regulation systems but they were absolute crap!
Yes, that just about sums up what he said! So, not a good idea, then? What about my cold feet? Will they be warm if the floor is insulated enough? So he's not telling porkies, then?
> The modern trend is for underfloor above the insulated screed or wall systems directly under the skim as they react quicker
Well that's interesting as the system we have in this little house is called Raychem Tyco T2 Reflecta. It's a heating cable set into an insulation sheet which goes on TOP of the screed. You then tile directly over it. As you say it heats up very quickly (and cools equally quickly) but it sounds really hollow - not nice and solid like a tiled floor should.
In reply to jon:
We're in a well insulated house with underfloor heating, we adjust the temperature by programming the timer increasing/decreasing the 'on time' in response to the weather. It's very comfortable provided you adjust the timer or manually turn the heating on/off early as required.
The heating is only on maybe 3 or 4 hours per day in winter (Glasgow). We've never tried running it 24 hrs and using room thermostats to adjust the temperature because the time lags are so long. The heating comes on an hour or two before we come home from work because the room temperature continues to rise for a couple of hours after the heating goes off.
I reckon an outdoor/indoor temperature sensors that adjusted the switch on/off times would work well - that's effectively what we do semi-manually. Alternatively I should do something clever with a raspberry pi to look up the weather forecast online and put the heating on earlier if it's going to be cold.
We're in a well insulated house with underfloor heating, we adjust the temperature by programming the timer increasing/decreasing the 'on time' in response to the weather. It's very comfortable provided you adjust the timer or manually turn the heating on/off early as required.
The heating is only on maybe 3 or 4 hours per day in winter (Glasgow). We've never tried running it 24 hrs and using room thermostats to adjust the temperature because the time lags are so long. The heating comes on an hour or two before we come home from work because the room temperature continues to rise for a couple of hours after the heating goes off.
I reckon an outdoor/indoor temperature sensors that adjusted the switch on/off times would work well - that's effectively what we do semi-manually. Alternatively I should do something clever with a raspberry pi to look up the weather forecast online and put the heating on earlier if it's going to be cold.
In reply to jon:
We lump them all together into energy-saving houses but then have different levels depending on the kWh/m² so they are generally just known as kW60 or whatever down to passive or plue-energy houses. The actual low-energy houses here are the ones built to the worst permissable standard so probably similar to RT2012.
You´ll always have cold feet on a tiled floor, the conductivity of tile systems makes it inevitable. I had one house with low-temperature underfloor and tiles and it always felt cold underfoot. My current hut has wood flooring and carpets. Slippers are the general answer!
The modern trend is to wall heating which is more efficient (so they tell me) running off a ground water heat pump but air/air is common enough, my neighbour has it. Wall heating has a big advantage it is cheap/easy enough to repair if you have an expensive flooring system installed and normally cheaper to install as well.
We lump them all together into energy-saving houses but then have different levels depending on the kWh/m² so they are generally just known as kW60 or whatever down to passive or plue-energy houses. The actual low-energy houses here are the ones built to the worst permissable standard so probably similar to RT2012.
You´ll always have cold feet on a tiled floor, the conductivity of tile systems makes it inevitable. I had one house with low-temperature underfloor and tiles and it always felt cold underfoot. My current hut has wood flooring and carpets. Slippers are the general answer!
The modern trend is to wall heating which is more efficient (so they tell me) running off a ground water heat pump but air/air is common enough, my neighbour has it. Wall heating has a big advantage it is cheap/easy enough to repair if you have an expensive flooring system installed and normally cheaper to install as well.
In reply to elsewhere:
This is what has been tried (in fact it was required for new systems) with outdoor sensors which worked together with the indoor system to try to adapt the heating level to what was going on outside. Most people disconnected them and were happier for it!
The problem is where Jon and I live the sun in the winter is quite strong so in the middle of winter the air temp will get up to maybe 20° but a few hours later it´s back down to 0° (or -20 on bad day). It´s particularly a hassle in autumn and spring where the outside sensor is basically talking bollocks to a slowly responding heating system. Mine was particularly rubbish since it used the average temperature to decide how much heat to store for the next three days so if a cold spell came after 3 warm ones we were doomed to freeze. Wire-cutters solved the problem
> I reckon an outdoor/indoor temperature sensors that adjusted the switch on/off times would work well - that's effectively what we do semi-manually. Alternatively I should do something clever with a raspberry pi to look up the weather forecast online and put the heating on earlier if it's going to be cold.
This is what has been tried (in fact it was required for new systems) with outdoor sensors which worked together with the indoor system to try to adapt the heating level to what was going on outside. Most people disconnected them and were happier for it!
The problem is where Jon and I live the sun in the winter is quite strong so in the middle of winter the air temp will get up to maybe 20° but a few hours later it´s back down to 0° (or -20 on bad day). It´s particularly a hassle in autumn and spring where the outside sensor is basically talking bollocks to a slowly responding heating system. Mine was particularly rubbish since it used the average temperature to decide how much heat to store for the next three days so if a cold spell came after 3 warm ones we were doomed to freeze. Wire-cutters solved the problem
In reply to jimtitt:
RT2012 is 50kWh/m².
When you say wall heating I assume you mean the air > air heater that we've been proposed? This one http://pompeachaleurdaikin.fr/nosproduits/emura/
Hmmm, it does seem from what you and our architect say that u/f might not be a great idea - you're not flogging him air to air units, are you? Costly - and even more so if we had to retro fit the system that they propose...
RT2012 is 50kWh/m².
When you say wall heating I assume you mean the air > air heater that we've been proposed? This one http://pompeachaleurdaikin.fr/nosproduits/emura/
Hmmm, it does seem from what you and our architect say that u/f might not be a great idea - you're not flogging him air to air units, are you? Costly - and even more so if we had to retro fit the system that they propose...
Post edited at 20:58
In reply to jon:
I can't imagine why a well designed underfloor system would be unsuitable. That said there are many design choices to make which could mean the difference between success and cold toes.
The heat source and the heat delivery can be considered independently. Some heat sources are better suited to UFCH than others but the heat source doesn't dictate the delivery so you could have an air to air heat pump along with UFCH if you wanted.
The response of UFCH is highly dependant on where in the floor the insulating layer sits. Essentially you can have (from the bottom up) concrete, insulation, screed or insulation, concrete, screed. If you put the insulation above the concrete you have a floor with less thermal mass so it will behave more like a radiator, heat up relatively quickly and cool down equally quickly. Insulation at the bottom means the floor will react very slowly but of course also hold its heat for much longer, acting as a stabilising element. (I assume we're talking concrete floors here). Our system, with the insulation above the concrete starts to feel warm in about 20 minutes from cold.
You don't say where you are or what the likely outside average is but bear in mind that air to air heat pumps have a few downsides. For a start they need a sodding big fan to get lots of air moving through the outside exchanger. That fan will inevitably be noisy, maybe not on day one but as it ages it will be noisy. They are also crap once the outside temperature drops too low, essentially they need to drive the outside part's temperature down in order to drive the inside part's temperature up and it's a constant battle for the system to stop condensation on the outside part from freezing.
I have a blown heating system using an air to air exchanger at work and yes, technically it works, it generates a constant room temperature, but I would never have on in a house - it's horrible.
I also have a mixture of radiators and UFCH on concrete and UFCH on suspended wood at home and the UFCH is great. If I were building from scratch it would be UFCH, no question.
I can't imagine why a well designed underfloor system would be unsuitable. That said there are many design choices to make which could mean the difference between success and cold toes.
The heat source and the heat delivery can be considered independently. Some heat sources are better suited to UFCH than others but the heat source doesn't dictate the delivery so you could have an air to air heat pump along with UFCH if you wanted.
The response of UFCH is highly dependant on where in the floor the insulating layer sits. Essentially you can have (from the bottom up) concrete, insulation, screed or insulation, concrete, screed. If you put the insulation above the concrete you have a floor with less thermal mass so it will behave more like a radiator, heat up relatively quickly and cool down equally quickly. Insulation at the bottom means the floor will react very slowly but of course also hold its heat for much longer, acting as a stabilising element. (I assume we're talking concrete floors here). Our system, with the insulation above the concrete starts to feel warm in about 20 minutes from cold.
You don't say where you are or what the likely outside average is but bear in mind that air to air heat pumps have a few downsides. For a start they need a sodding big fan to get lots of air moving through the outside exchanger. That fan will inevitably be noisy, maybe not on day one but as it ages it will be noisy. They are also crap once the outside temperature drops too low, essentially they need to drive the outside part's temperature down in order to drive the inside part's temperature up and it's a constant battle for the system to stop condensation on the outside part from freezing.
I have a blown heating system using an air to air exchanger at work and yes, technically it works, it generates a constant room temperature, but I would never have on in a house - it's horrible.
I also have a mixture of radiators and UFCH on concrete and UFCH on suspended wood at home and the UFCH is great. If I were building from scratch it would be UFCH, no question.
In reply to csambrook:
I'm in Provence. Our old house in the alps had concrete, insulation/heating element, 5cm screed, tiles and it used to take 24 hours to heat up from cold. The house here in Provence is 200 years old and the walls are huge heat sinks. The floor is (now) concrete, screed, insulation/heating element, tiles. As the element is only heating effectively the tiles it heats up in about half an hour, but we don't really like it for various reasons - the hollow sound being one. One thought that we had some time back was to install the u/f system so we could fall back on it if we didn't like the proposed system (or just forget it if the air > air was OK - I've seen prices of 40 > 50€/m² for electric u/f which wouldn't be too bad - if correct). However, our advice has been to just forget it and go with air > air.
I'm in Provence. Our old house in the alps had concrete, insulation/heating element, 5cm screed, tiles and it used to take 24 hours to heat up from cold. The house here in Provence is 200 years old and the walls are huge heat sinks. The floor is (now) concrete, screed, insulation/heating element, tiles. As the element is only heating effectively the tiles it heats up in about half an hour, but we don't really like it for various reasons - the hollow sound being one. One thought that we had some time back was to install the u/f system so we could fall back on it if we didn't like the proposed system (or just forget it if the air > air was OK - I've seen prices of 40 > 50€/m² for electric u/f which wouldn't be too bad - if correct). However, our advice has been to just forget it and go with air > air.
In reply to jon:
I've no idea about under floor heating but I once lived in a house with hot air heating and it was shit. It heated one room but was like having a massive hand drier in the wall and the rest of the house was cold. I wouldn't live in a place with it again.
I've no idea about under floor heating but I once lived in a house with hot air heating and it was shit. It heated one room but was like having a massive hand drier in the wall and the rest of the house was cold. I wouldn't live in a place with it again.
In reply to jon:
It´s just like underfloor but you put it in the walls instead, either electric which is fairly uncommon or water. Either the tubing is put onto the insulation and plastered over or you can get finished insulation/piping elements which are fitted as if you were dry-lining and then plasterboard over the top. Just Google wall heating systems and you´ll find plenty of info!
> RT2012 is 50kWh/m².
> When you say wall heating I assume you mean the air > air heater that we've been proposed? This one http://pompeachaleurdaikin.fr/nosproduits/emura/
> Hmmm, it does seem from what you and our architect say that u/f might not be a great idea - you're not flogging him air to air units, are you? Costly - and even more so if we had to retro fit the system that they propose...
It´s just like underfloor but you put it in the walls instead, either electric which is fairly uncommon or water. Either the tubing is put onto the insulation and plastered over or you can get finished insulation/piping elements which are fitted as if you were dry-lining and then plasterboard over the top. Just Google wall heating systems and you´ll find plenty of info!
In reply to jimtitt:
I'd never heard of that. I can see the advantages of easy(ish) access if it goes wrong, but not sure I'd want walls radiating heat at me. Or would I? Got to be better than heated ceilings, though.
I'd never heard of that. I can see the advantages of easy(ish) access if it goes wrong, but not sure I'd want walls radiating heat at me. Or would I? Got to be better than heated ceilings, though.
In reply to elsewhere:
Ah, well as I'm now retired I spend quite a bit of time in the house during the day (if I'm not climbing...). This is another reason why our heating is on permanently.
> The heating is only on maybe 3 or 4 hours per day in winter
Ah, well as I'm now retired I spend quite a bit of time in the house during the day (if I'm not climbing...). This is another reason why our heating is on permanently.
In reply to the power:
But I don't know which your website is - googling that comes up with dozens of things.
> Google UK underfloor heating in Sheffield masses of info on our website
But I don't know which your website is - googling that comes up with dozens of things.
1
In reply to jon:
I would perhaps consider an underfloor heating system designed to satisfy the total room heat loss, but set to achieve a lower output and used in conjunction with an air source heat pump. This way, the underfloor heating could be used to just 'lift' the floor contact temperature and if needed, the air source heat pump could act as a means of addressing the fluctuating and fast response loads/gain.
There is of-course the noise generated by air source heat pumps, which personally i would not like to live with as the sole means of providing heat. The plus side of air source heat pumps is that in the summer, if you need cooling, then this will also be provided by the air source heat pump.
If you are out there and the architect has already completed a similar project to what they are proposing, then it may be an idea to ask if you can visit that project and perhaps talk to the occupants.
Whilst not wishing to be disparaging to architects....that is what they are, and not engineers or designers of heating/cooling/ventilation systems.
I would perhaps consider an underfloor heating system designed to satisfy the total room heat loss, but set to achieve a lower output and used in conjunction with an air source heat pump. This way, the underfloor heating could be used to just 'lift' the floor contact temperature and if needed, the air source heat pump could act as a means of addressing the fluctuating and fast response loads/gain.
There is of-course the noise generated by air source heat pumps, which personally i would not like to live with as the sole means of providing heat. The plus side of air source heat pumps is that in the summer, if you need cooling, then this will also be provided by the air source heat pump.
If you are out there and the architect has already completed a similar project to what they are proposing, then it may be an idea to ask if you can visit that project and perhaps talk to the occupants.
Whilst not wishing to be disparaging to architects....that is what they are, and not engineers or designers of heating/cooling/ventilation systems.
In reply to jon:
I used to be a bit sceptical about underfloor heating.maybe I still am. Slightly
All I would say is that the underfloor heating will certainly get rid of the cold tiles ,which is not pleasant.
Whether it is any more effective at ,efficiently ,heating your home than radiators is open to argument.
Most of the plumbers I work with ,reckon there's nothing in it.
However for the sake of having warm feet (important) ,I would go with under floor.assuming it's tiled floors?
I used to be a bit sceptical about underfloor heating.maybe I still am. Slightly
All I would say is that the underfloor heating will certainly get rid of the cold tiles ,which is not pleasant.
Whether it is any more effective at ,efficiently ,heating your home than radiators is open to argument.
Most of the plumbers I work with ,reckon there's nothing in it.
However for the sake of having warm feet (important) ,I would go with under floor.assuming it's tiled floors?
In reply to Ali.B:
Yes, that's exactly what we did in our house in the alps but in conjunction with a wood stove. The floor was set at 15° which meant that when you came in on a cold day it immediately felt warm and welcoming. At that temperature of course, after ten minutes or so it didn't feel so warm and so I'd light the fire. But that's the sort of thing I was wanting to do with the new house - have a background heat, topped up by another heat source, not heat entirely by u/f.
You're right but in this case the architect I refer to is the in-house architect of the construction company. It equally has other specialists/engineers. However I guess above I referred to the architect when maybe I should have referred to the construction company.
> but set to achieve a lower output and used in conjunction with an air source heat pump.
Yes, that's exactly what we did in our house in the alps but in conjunction with a wood stove. The floor was set at 15° which meant that when you came in on a cold day it immediately felt warm and welcoming. At that temperature of course, after ten minutes or so it didn't feel so warm and so I'd light the fire. But that's the sort of thing I was wanting to do with the new house - have a background heat, topped up by another heat source, not heat entirely by u/f.
> Whilst not wishing to be disparaging to architects....that is what they are, and not engineers or designers of heating/cooling/ventilation systems.
You're right but in this case the architect I refer to is the in-house architect of the construction company. It equally has other specialists/engineers. However I guess above I referred to the architect when maybe I should have referred to the construction company.
In reply to jon:
Well, I had thought - mindset of construction in warm places. We have a heat pump in our very badly insulated hose in FL. It's OK except in the ~2 weeks of the year when it's actually cold. So I thought "bet you can't get underfloor heating in FL which has the same issues as Provence (wildly changing temperatures in winter, although it only rarely gets to freezing)". And what do I find -
http://www.infrafloor.com/blog/underfloor-heating-in-brooksville-florida/
which is about 50 miles N of us.
I would say that heat pumps are not too good at getting rid of cold in my experience and your plan is a good one. Although that may reflect heat pumps in FL. I have a feeling that heat pumps work best when the temperature differential is not too great (i.e you want to drop the temperature by about 10 degrees) and not so good when you want to increase it by >20 degrees.
On the noise issue - yes that is mildly annoying, but you get completely used to it. Our HVAC unit is right outside the bedroom window and it doesn't bother me.
Well, I had thought - mindset of construction in warm places. We have a heat pump in our very badly insulated hose in FL. It's OK except in the ~2 weeks of the year when it's actually cold. So I thought "bet you can't get underfloor heating in FL which has the same issues as Provence (wildly changing temperatures in winter, although it only rarely gets to freezing)". And what do I find -
http://www.infrafloor.com/blog/underfloor-heating-in-brooksville-florida/
which is about 50 miles N of us.
I would say that heat pumps are not too good at getting rid of cold in my experience and your plan is a good one. Although that may reflect heat pumps in FL. I have a feeling that heat pumps work best when the temperature differential is not too great (i.e you want to drop the temperature by about 10 degrees) and not so good when you want to increase it by >20 degrees.
On the noise issue - yes that is mildly annoying, but you get completely used to it. Our HVAC unit is right outside the bedroom window and it doesn't bother me.
In reply to jon:
Lived in a house with underfloor heating for forty years, would not have anything else - although this is not very efficient with a cork tile floor that almost insulates the rooms against the heat! It is on economy seven overnight rates of course - too expensive to run in the day. Was once in a house with blown air heating - created far too much movement of air. I suspect current underfloor systems are much more efficient now.
Lived in a house with underfloor heating for forty years, would not have anything else - although this is not very efficient with a cork tile floor that almost insulates the rooms against the heat! It is on economy seven overnight rates of course - too expensive to run in the day. Was once in a house with blown air heating - created far too much movement of air. I suspect current underfloor systems are much more efficient now.
In reply to jon:
I'd go for UFH if I were you. Unless your construction company's consultants can give compelling enough evidence or reason not to - and it clearly sounds like they haven't thus far - they should give you, the paying client, what you've asked for. You can predict reasonably accurately when it's going to be sufficiently cold to warrant using the UFH, but if you're concerned about needing faster heat, you can always have local electric heaters. I've always found air heaters give poor quality heat ie it's dry and seems very temporary.
Could you try another contractor & set of consultants if these guys dig in their heels or had construction started already?
Edit: I'd agree with Ali B's comment about the architect not being the best qualified to advise, I'd always bow to an M&E consultant's expertise in such matters.
I'd go for UFH if I were you. Unless your construction company's consultants can give compelling enough evidence or reason not to - and it clearly sounds like they haven't thus far - they should give you, the paying client, what you've asked for. You can predict reasonably accurately when it's going to be sufficiently cold to warrant using the UFH, but if you're concerned about needing faster heat, you can always have local electric heaters. I've always found air heaters give poor quality heat ie it's dry and seems very temporary.
Could you try another contractor & set of consultants if these guys dig in their heels or had construction started already?
Edit: I'd agree with Ali B's comment about the architect not being the best qualified to advise, I'd always bow to an M&E consultant's expertise in such matters.
Post edited at 13:32
In reply to altirando:
Well yes, me too. It's the energy saving house bit that seems to be the spanner in the works. If the house isn't efficient and heat escapes everywhere (like our house here) then the floor heating stays on to keep up with the loss. A more efficient house apparently prevents it from doing that and it's the inertia that's the problem.
Peter, the noise does bother me. The unit they propose is apparently very quiet (in the house) 19 decibels, I think it was but maybe wrong. Outside it'll be position as far away from living/sleeping areas as possible. Probably piss the neighbour off, though.
> Lived in a house with underfloor heating for forty years, would not have anything else
Well yes, me too. It's the energy saving house bit that seems to be the spanner in the works. If the house isn't efficient and heat escapes everywhere (like our house here) then the floor heating stays on to keep up with the loss. A more efficient house apparently prevents it from doing that and it's the inertia that's the problem.
Peter, the noise does bother me. The unit they propose is apparently very quiet (in the house) 19 decibels, I think it was but maybe wrong. Outside it'll be position as far away from living/sleeping areas as possible. Probably piss the neighbour off, though.
In reply to Fraser:
Thanks Fraser. They won't dig their heels in - they've already said we could have it but advised quite strongly against. No, too late to change contractors - digging starts end Jan and 10% paid! Besides I like their houses!
Thanks Fraser. They won't dig their heels in - they've already said we could have it but advised quite strongly against. No, too late to change contractors - digging starts end Jan and 10% paid! Besides I like their houses!
In reply to jon:
Agreed - the outside unit is the noisy bit with the compressor and everything. Noise level depends on whether you have a package unit or separate units (package unit has the cooling heating coils with the compressor unit, separates have the cooling/heating unit in the house (usually the garage) which means you can put the compressor miles away as it doesn't need to have the house air pumped through it).
If it's an energy efficient house, it likely has decent sound insulation as a by-product. 19db is barely audible.
I think their argument is that underfloor heating is likely overkill, but if you like a warm floor, it's definitely not. And the lag is definitely an issue for someone who wants "instant on/off" heat - but if you allow for it then it's not.
Agreed - the outside unit is the noisy bit with the compressor and everything. Noise level depends on whether you have a package unit or separate units (package unit has the cooling heating coils with the compressor unit, separates have the cooling/heating unit in the house (usually the garage) which means you can put the compressor miles away as it doesn't need to have the house air pumped through it).
If it's an energy efficient house, it likely has decent sound insulation as a by-product. 19db is barely audible.
I think their argument is that underfloor heating is likely overkill, but if you like a warm floor, it's definitely not. And the lag is definitely an issue for someone who wants "instant on/off" heat - but if you allow for it then it's not.
In reply to jon:
Another point that is worth mentioning is that if you are able to modulate the heating water temperature from a heat pump closer to that required for the underfloor heating, the heat pump will work more efficiently.
Hope it all goes well for you.
Another point that is worth mentioning is that if you are able to modulate the heating water temperature from a heat pump closer to that required for the underfloor heating, the heat pump will work more efficiently.
Hope it all goes well for you.
In reply to jon:
You're quite close to us (we're about the same distance north of Serres as you are west) but we're higher, so colder winters and cooler summers.
You might already be getting the right kind of advice (although it sounds from your OP possibly not) but I can recommend this guy in our village specializes in advising on new builds and rennovations when it comes to energy efficiency etc - we're renovating and he's done a thermal studies on our place and is helping us with options. I'd definitely recommend him.
http://www.fildair.fr
You're quite close to us (we're about the same distance north of Serres as you are west) but we're higher, so colder winters and cooler summers.
You might already be getting the right kind of advice (although it sounds from your OP possibly not) but I can recommend this guy in our village specializes in advising on new builds and rennovations when it comes to energy efficiency etc - we're renovating and he's done a thermal studies on our place and is helping us with options. I'd definitely recommend him.
http://www.fildair.fr
In reply to jon:
Not always I guess. Bit of an unfair comment after a frustrating week of sorting out an architects mess. I don't know yours but a lot I come across are arrogant and wrong more often than not. My guess is you'd make his life easier by putting in an air to air.
I did a research project on ground source heat pumps so am bias. I'm a big fan providing its thermostat controlled. More efficient than air and no drafts which result in heat loss. I also lived with an air to air for a few months. Noisy, ugly but it did heat the house quick. You then get it switching back on when you're in middle of something.
Not always I guess. Bit of an unfair comment after a frustrating week of sorting out an architects mess. I don't know yours but a lot I come across are arrogant and wrong more often than not. My guess is you'd make his life easier by putting in an air to air.
I did a research project on ground source heat pumps so am bias. I'm a big fan providing its thermostat controlled. More efficient than air and no drafts which result in heat loss. I also lived with an air to air for a few months. Noisy, ugly but it did heat the house quick. You then get it switching back on when you're in middle of something.
In reply to yarbles:
When I used to work for architects (way back in another life) we always delighted in telling clients that RIBA stood for remember I'm the bloody architect! To be fair I don't think it'd make his life any easier at all. He just thinks it'd be a bit of overkill as well as being more difficult to regulate. Basically a waste of money for us. Interestingly I did briefly wonder about a ground source heat pump but never got any further than that - having fifty or so olive trees that we're not allowed to get rid of (local by law), only move to make room for the house, might complicate things as far as that is concerned.
When I used to work for architects (way back in another life) we always delighted in telling clients that RIBA stood for remember I'm the bloody architect! To be fair I don't think it'd make his life any easier at all. He just thinks it'd be a bit of overkill as well as being more difficult to regulate. Basically a waste of money for us. Interestingly I did briefly wonder about a ground source heat pump but never got any further than that - having fifty or so olive trees that we're not allowed to get rid of (local by law), only move to make room for the house, might complicate things as far as that is concerned.
Post edited at 21:26
In reply to jon:
For god's sake avoid Air to Air heat pumps. 7 years experience of them, built into the house originally with all the promises of low energy bills , quiet operation and effective heating. Rubbish on every count and deeply unreliable.
Ended up putting a gas boiler in and radiators, house is toasty now and the bills are lower.
For god's sake avoid Air to Air heat pumps. 7 years experience of them, built into the house originally with all the promises of low energy bills , quiet operation and effective heating. Rubbish on every count and deeply unreliable.
Ended up putting a gas boiler in and radiators, house is toasty now and the bills are lower.
In reply to jon:
We've just bought a house with air/air heating (and cooling) systems installed about 5 years ago and there are a few drawbacks. First the fan noise, mostly inside, you wouldn't want to sleep in a room with the heating on. The outside fans aren't so noisy unless they come on at night when you are asleep but they don't normally. Generally you don't put the heating on much in the evening. if the house is well insulated anyway. Secondly they don't work when the outside temperature drops below about 9°C so you need a secondary system, which in our case is a wood fire. The house is about 14 years old so may not be up to the latest standards - level C on the house add measures. The other doubt I have is what will happen when it goes wrong? Specialists for heat exchange systems are not so common as for gas heating systems around Paris.
As we have access to free wood now and then we use the wood fire as the main heating system and just put the electric heaters in the morning or when we come in. Over the year the heat-pump system works out quite economical. I'm not sure how I'd like it as main heating, all too high-tech, on the other hand over a year now and no problems.
We've just bought a house with air/air heating (and cooling) systems installed about 5 years ago and there are a few drawbacks. First the fan noise, mostly inside, you wouldn't want to sleep in a room with the heating on. The outside fans aren't so noisy unless they come on at night when you are asleep but they don't normally. Generally you don't put the heating on much in the evening. if the house is well insulated anyway. Secondly they don't work when the outside temperature drops below about 9°C so you need a secondary system, which in our case is a wood fire. The house is about 14 years old so may not be up to the latest standards - level C on the house add measures. The other doubt I have is what will happen when it goes wrong? Specialists for heat exchange systems are not so common as for gas heating systems around Paris.
As we have access to free wood now and then we use the wood fire as the main heating system and just put the electric heaters in the morning or when we come in. Over the year the heat-pump system works out quite economical. I'm not sure how I'd like it as main heating, all too high-tech, on the other hand over a year now and no problems.
In reply to jon:
I have a friend in the Drome who has installed that, cost about 40 000 € what with all the drilling - he is on limestone, but now he has more or less free energy. It dépends on how long he lives to know if it's economic After 100 years old he'll be quids in.
I have a friend in the Drome who has installed that, cost about 40 000 € what with all the drilling - he is on limestone, but now he has more or less free energy. It dépends on how long he lives to know if it's economic After 100 years old he'll be quids in.
In reply to Bruce Hooker:
Well Bruce, there are different types. There's the type that your friend has where they drill two very deep holes. Then there's the type where you bury a long loop of tubing at a relatively shallow depth - a bit like this: http://americandreamgeothermal.com/geothermal-heat-pump-summary/ This needs no drilling. But I think our olive trees might be a bit of an obstacle. Also, it'd never repay itself in my lifetime!
Well Bruce, there are different types. There's the type that your friend has where they drill two very deep holes. Then there's the type where you bury a long loop of tubing at a relatively shallow depth - a bit like this: http://americandreamgeothermal.com/geothermal-heat-pump-summary/ This needs no drilling. But I think our olive trees might be a bit of an obstacle. Also, it'd never repay itself in my lifetime!
Post edited at 20:57
In reply to jon:
Yes I know about the shallow pipe system, my brother tried to sell them for a bit, and you don't need much land either but the economics have never seemed convincing... especially when you are getting on a bit, getting my money back in 20 years doesn't have much appeal to me nowadays! Often I think it is more an ecological statement, the pleasure of having a system which costs next to nothing to run. In our present house I would have preferred gas but there is no gas in the village so it had to be electricity... Cooking on gas is better too, I'm just starting to get used to these induction rings but even so end up burning the dinner pretty often.
The other slight hang up with our pompes à chaleurs is they are individually controlled by remote controls like TVs, there is no central control system. I don't know if more recent systems are different but it would be a question to ask, especially if you want a timer to control the heating.
Yes I know about the shallow pipe system, my brother tried to sell them for a bit, and you don't need much land either but the economics have never seemed convincing... especially when you are getting on a bit, getting my money back in 20 years doesn't have much appeal to me nowadays! Often I think it is more an ecological statement, the pleasure of having a system which costs next to nothing to run. In our present house I would have preferred gas but there is no gas in the village so it had to be electricity... Cooking on gas is better too, I'm just starting to get used to these induction rings but even so end up burning the dinner pretty often.
The other slight hang up with our pompes à chaleurs is they are individually controlled by remote controls like TVs, there is no central control system. I don't know if more recent systems are different but it would be a question to ask, especially if you want a timer to control the heating.
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